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<li class="chapter" data-level="" data-path="index.html"><a href="index.html"><i class="fa fa-check"></i>欢迎</a>
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<li class="chapter" data-level="" data-path="abstract.html"><a href="abstract.html"><i class="fa fa-check"></i>内容概要</a></li>
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<li class="chapter" data-level="1" data-path="data-read-write-description.html"><a href="data-read-write-description.html"><i class="fa fa-check"></i><b>1</b> 数据导入导出</a>
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<li class="chapter" data-level="1.1" data-path="readxl-description.html"><a href="readxl-description.html"><i class="fa fa-check"></i><b>1.1</b> readxl</a>
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<li class="chapter" data-level="1.1.1" data-path="readxl-description.html"><a href="readxl-description.html#readxl:install"><i class="fa fa-check"></i><b>1.1.1</b> 安装</a></li>
<li class="chapter" data-level="1.1.2" data-path="readxl-description.html"><a href="readxl-description.html#readxl:usage"><i class="fa fa-check"></i><b>1.1.2</b> 用法</a></li>
<li class="chapter" data-level="1.1.3" data-path="readxl-description.html"><a href="readxl-description.html#batch:read"><i class="fa fa-check"></i><b>1.1.3</b> 批量读取</a></li>
<li class="chapter" data-level="1.1.4" data-path="readxl-description.html"><a href="readxl-description.html#batch:write"><i class="fa fa-check"></i><b>1.1.4</b> 批量输出</a></li>
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<li class="chapter" data-level="1.2" data-path="writexl.html"><a href="writexl.html"><i class="fa fa-check"></i><b>1.2</b> writexl</a>
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<li class="chapter" data-level="1.2.1" data-path="writexl.html"><a href="writexl.html#writexl:usage"><i class="fa fa-check"></i><b>1.2.1</b> 用法</a></li>
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<li class="chapter" data-level="1.3" data-path="openxlsx-description.html"><a href="openxlsx-description.html"><i class="fa fa-check"></i><b>1.3</b> openxlsx</a>
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<li class="chapter" data-level="1.3.1" data-path="openxlsx-description.html"><a href="openxlsx-description.html#openxlsx:install"><i class="fa fa-check"></i><b>1.3.1</b> 安装</a></li>
<li class="chapter" data-level="1.3.2" data-path="openxlsx-description.html"><a href="openxlsx-description.html#openxlsx:functions"><i class="fa fa-check"></i><b>1.3.2</b> 基础功能</a></li>
<li class="chapter" data-level="1.3.3" data-path="openxlsx-description.html"><a href="openxlsx-description.html#定制格式输出"><i class="fa fa-check"></i><b>1.3.3</b> 定制格式输出</a></li>
<li class="chapter" data-level="1.3.4" data-path="openxlsx-description.html"><a href="openxlsx-description.html#函数参数"><i class="fa fa-check"></i><b>1.3.4</b> 函数参数</a></li>
<li class="chapter" data-level="1.3.5" data-path="openxlsx-description.html"><a href="openxlsx-description.html#总结"><i class="fa fa-check"></i><b>1.3.5</b> 总结</a></li>
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<li class="chapter" data-level="1.4" data-path="readr-package.html"><a href="readr-package.html"><i class="fa fa-check"></i><b>1.4</b> readr</a>
<ul>
<li class="chapter" data-level="1.4.1" data-path="readr-package.html"><a href="readr-package.html#readr:install"><i class="fa fa-check"></i><b>1.4.1</b> 安装</a></li>
<li class="chapter" data-level="1.4.2" data-path="readr-package.html"><a href="readr-package.html#readr:usage"><i class="fa fa-check"></i><b>1.4.2</b> 用法</a></li>
<li class="chapter" data-level="1.4.3" data-path="readr-package.html"><a href="readr-package.html#readr:write-function"><i class="fa fa-check"></i><b>1.4.3</b> 导出功能</a></li>
<li class="chapter" data-level="1.4.4" data-path="readr-package.html"><a href="readr-package.html#总结-1"><i class="fa fa-check"></i><b>1.4.4</b> 总结</a></li>
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<li class="chapter" data-level="1.5" data-path="data-vroom.html"><a href="data-vroom.html"><i class="fa fa-check"></i><b>1.5</b> vroom</a>
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<li class="chapter" data-level="1.5.1" data-path="data-vroom.html"><a href="data-vroom.html#安装"><i class="fa fa-check"></i><b>1.5.1</b> 安装</a></li>
<li class="chapter" data-level="1.5.2" data-path="data-vroom.html"><a href="data-vroom.html#用法"><i class="fa fa-check"></i><b>1.5.2</b> 用法</a></li>
</ul></li>
<li class="chapter" data-level="1.6" data-path="data-rstudio-addins.html"><a href="data-rstudio-addins.html"><i class="fa fa-check"></i><b>1.6</b> Rstudio导入</a>
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<li class="chapter" data-level="1.6.1" data-path="data-rstudio-addins.html"><a href="data-rstudio-addins.html#rstudio-工具栏导入"><i class="fa fa-check"></i><b>1.6.1</b> rstudio 工具栏导入</a></li>
<li class="chapter" data-level="1.6.2" data-path="data-rstudio-addins.html"><a href="data-rstudio-addins.html#插件导入"><i class="fa fa-check"></i><b>1.6.2</b> 插件导入</a></li>
</ul></li>
<li class="chapter" data-level="1.7" data-path="data-file-path.html"><a href="data-file-path.html"><i class="fa fa-check"></i><b>1.7</b> 文件路径</a>
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<li class="chapter" data-level="1.7.1" data-path="data-file-path.html"><a href="data-file-path.html#指定路径"><i class="fa fa-check"></i><b>1.7.1</b> 指定路径</a></li>
<li class="chapter" data-level="1.7.2" data-path="data-file-path.html"><a href="data-file-path.html#默认路径"><i class="fa fa-check"></i><b>1.7.2</b> 默认路径</a></li>
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<li class="chapter" data-level="1.8" data-path="data-expand.html"><a href="data-expand.html"><i class="fa fa-check"></i><b>1.8</b> 拓展</a>
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<li class="chapter" data-level="1.8.1" data-path="data-expand.html"><a href="data-expand.html#tidyxl:package"><i class="fa fa-check"></i><b>1.8.1</b> tidyxl</a></li>
<li class="chapter" data-level="1.8.2" data-path="data-expand.html"><a href="data-expand.html#参考资料"><i class="fa fa-check"></i><b>1.8.2</b> 参考资料</a></li>
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</ul></li>
<li class="chapter" data-level="2" data-path="Data-Manipulation-dplyr.html"><a href="Data-Manipulation-dplyr.html"><i class="fa fa-check"></i><b>2</b> 数据处理之-dplyr</a>
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<li class="chapter" data-level="2.1" data-path="dplyr-description.html"><a href="dplyr-description.html"><i class="fa fa-check"></i><b>2.1</b> 前言</a>
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<li class="chapter" data-level="2.1.1" data-path="dplyr-description.html"><a href="dplyr-description.html#dplyr:install-package"><i class="fa fa-check"></i><b>2.1.1</b> 安装</a></li>
<li class="chapter" data-level="2.1.2" data-path="dplyr-description.html"><a href="dplyr-description.html#dplyr:difference-of-sql"><i class="fa fa-check"></i><b>2.1.2</b> Excel and Sql 类比</a></li>
<li class="chapter" data-level="2.1.3" data-path="dplyr-description.html"><a href="dplyr-description.html#常见问题"><i class="fa fa-check"></i><b>2.1.3</b> 常见问题</a></li>
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<li class="chapter" data-level="2.2" data-path="dplyr-usage.html"><a href="dplyr-usage.html"><i class="fa fa-check"></i><b>2.2</b> 基础用法</a>
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<li class="chapter" data-level="2.2.1" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-filter"><i class="fa fa-check"></i><b>2.2.1</b> filter</a></li>
<li class="chapter" data-level="2.2.2" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-select"><i class="fa fa-check"></i><b>2.2.2</b> select</a></li>
<li class="chapter" data-level="2.2.3" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-rename"><i class="fa fa-check"></i><b>2.2.3</b> rename</a></li>
<li class="chapter" data-level="2.2.4" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-relocate"><i class="fa fa-check"></i><b>2.2.4</b> relocate</a></li>
<li class="chapter" data-level="2.2.5" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-mutate"><i class="fa fa-check"></i><b>2.2.5</b> mutate</a></li>
<li class="chapter" data-level="2.2.6" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-arrange"><i class="fa fa-check"></i><b>2.2.6</b> arrange</a></li>
<li class="chapter" data-level="2.2.7" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-summarise"><i class="fa fa-check"></i><b>2.2.7</b> summarise</a></li>
<li class="chapter" data-level="2.2.8" data-path="dplyr-usage.html"><a href="dplyr-usage.html#dplyr-groupby"><i class="fa fa-check"></i><b>2.2.8</b> group_by</a></li>
</ul></li>
<li class="chapter" data-level="2.3" data-path="dplyr-functions.html"><a href="dplyr-functions.html"><i class="fa fa-check"></i><b>2.3</b> 常用函数</a>
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<li class="chapter" data-level="2.3.1" data-path="dplyr-functions.html"><a href="dplyr-functions.html#条件判断"><i class="fa fa-check"></i><b>2.3.1</b> 条件判断</a></li>
<li class="chapter" data-level="2.3.2" data-path="dplyr-functions.html"><a href="dplyr-functions.html#case_when"><i class="fa fa-check"></i><b>2.3.2</b> case_when</a></li>
<li class="chapter" data-level="2.3.3" data-path="dplyr-functions.html"><a href="dplyr-functions.html#计数函数"><i class="fa fa-check"></i><b>2.3.3</b> 计数函数</a></li>
<li class="chapter" data-level="2.3.4" data-path="dplyr-functions.html"><a href="dplyr-functions.html#排序函数"><i class="fa fa-check"></i><b>2.3.4</b> 排序函数</a></li>
<li class="chapter" data-level="2.3.5" data-path="dplyr-functions.html"><a href="dplyr-functions.html#提取向量"><i class="fa fa-check"></i><b>2.3.5</b> 提取向量</a></li>
<li class="chapter" data-level="2.3.6" data-path="dplyr-functions.html"><a href="dplyr-functions.html#dplyr:slice"><i class="fa fa-check"></i><b>2.3.6</b> slice 系列</a></li>
<li class="chapter" data-level="2.3.7" data-path="dplyr-functions.html"><a href="dplyr-functions.html#group-系列"><i class="fa fa-check"></i><b>2.3.7</b> group 系列</a></li>
<li class="chapter" data-level="2.3.8" data-path="dplyr-functions.html"><a href="dplyr-functions.html#其它函数"><i class="fa fa-check"></i><b>2.3.8</b> 其它函数</a></li>
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<li class="chapter" data-level="2.4" data-path="dplyr-merge-two-table.html"><a href="dplyr-merge-two-table.html"><i class="fa fa-check"></i><b>2.4</b> 表关联</a>
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<li class="chapter" data-level="2.4.1" data-path="dplyr-merge-two-table.html"><a href="dplyr-merge-two-table.html#dplyr:merge-table-usage"><i class="fa fa-check"></i><b>2.4.1</b> 两表关联</a></li>
<li class="chapter" data-level="2.4.2" data-path="dplyr-merge-two-table.html"><a href="dplyr-merge-two-table.html#dplyr:merge-multiple-table"><i class="fa fa-check"></i><b>2.4.2</b> 多表操作</a></li>
</ul></li>
<li class="chapter" data-level="2.5" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html"><i class="fa fa-check"></i><b>2.5</b> 分组操作</a>
<ul>
<li class="chapter" data-level="2.5.1" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html#添加分组"><i class="fa fa-check"></i><b>2.5.1</b> 添加分组</a></li>
<li class="chapter" data-level="2.5.2" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html#查看分组"><i class="fa fa-check"></i><b>2.5.2</b> 查看分组</a></li>
<li class="chapter" data-level="2.5.3" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html#更改和添加分组变量"><i class="fa fa-check"></i><b>2.5.3</b> 更改和添加分组变量</a></li>
<li class="chapter" data-level="2.5.4" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html#删除分组变量"><i class="fa fa-check"></i><b>2.5.4</b> 删除分组变量</a></li>
<li class="chapter" data-level="2.5.5" data-path="dplyr-groupby-manipulation.html"><a href="dplyr-groupby-manipulation.html#动词影响"><i class="fa fa-check"></i><b>2.5.5</b> 动词影响</a></li>
</ul></li>
<li class="chapter" data-level="2.6" data-path="dplyr-column-manipulation.html"><a href="dplyr-column-manipulation.html"><i class="fa fa-check"></i><b>2.6</b> 列操作</a>
<ul>
<li class="chapter" data-level="2.6.1" data-path="dplyr-column-manipulation.html"><a href="dplyr-column-manipulation.html#dplyr-column-manipulation-basic-usage"><i class="fa fa-check"></i><b>2.6.1</b> 基础用法</a></li>
<li class="chapter" data-level="2.6.2" data-path="dplyr-column-manipulation.html"><a href="dplyr-column-manipulation.html#多种函数功能"><i class="fa fa-check"></i><b>2.6.2</b> 多种函数功能</a></li>
<li class="chapter" data-level="2.6.3" data-path="dplyr-column-manipulation.html"><a href="dplyr-column-manipulation.html#当前列"><i class="fa fa-check"></i><b>2.6.3</b> 当前列</a></li>
</ul></li>
<li class="chapter" data-level="2.7" data-path="dplyr-row-manipulation.html"><a href="dplyr-row-manipulation.html"><i class="fa fa-check"></i><b>2.7</b> 行操作</a>
<ul>
<li class="chapter" data-level="2.7.1" data-path="dplyr-row-manipulation.html"><a href="dplyr-row-manipulation.html#比较差异"><i class="fa fa-check"></i><b>2.7.1</b> 比较差异</a></li>
<li class="chapter" data-level="2.7.2" data-path="dplyr-row-manipulation.html"><a href="dplyr-row-manipulation.html#常用案例"><i class="fa fa-check"></i><b>2.7.2</b> 常用案例</a></li>
</ul></li>
<li class="chapter" data-level="2.8" data-path="dplyr-programming.html"><a href="dplyr-programming.html"><i class="fa fa-check"></i><b>2.8</b> <code>dplyr</code>编程</a>
<ul>
<li class="chapter" data-level="2.8.1" data-path="dplyr-programming.html"><a href="dplyr-programming.html#案例"><i class="fa fa-check"></i><b>2.8.1</b> 案例</a></li>
</ul></li>
<li class="chapter" data-level="2.9" data-path="dplyr-reference-material.html"><a href="dplyr-reference-material.html"><i class="fa fa-check"></i><b>2.9</b> 参考资料</a></li>
</ul></li>
<li class="chapter" data-level="3" data-path="Data-tidyr-package.html"><a href="Data-tidyr-package.html"><i class="fa fa-check"></i><b>3</b> 整洁数据之 tidyr</a>
<ul>
<li class="chapter" data-level="3.1" data-path="tidyr-useage.html"><a href="tidyr-useage.html"><i class="fa fa-check"></i><b>3.1</b> tidyr 介绍</a>
<ul>
<li class="chapter" data-level="3.1.1" data-path="tidyr-useage.html"><a href="tidyr-useage.html#tidyr:install"><i class="fa fa-check"></i><b>3.1.1</b> 安装</a></li>
<li class="chapter" data-level="3.1.2" data-path="tidyr-useage.html"><a href="tidyr-useage.html#tidyr:functions"><i class="fa fa-check"></i><b>3.1.2</b> 主要功能</a></li>
</ul></li>
<li class="chapter" data-level="3.2" data-path="pivoting.html"><a href="pivoting.html"><i class="fa fa-check"></i><b>3.2</b> 长宽转换</a>
<ul>
<li class="chapter" data-level="3.2.1" data-path="pivoting.html"><a href="pivoting.html#宽转长"><i class="fa fa-check"></i><b>3.2.1</b> 宽转长</a></li>
<li class="chapter" data-level="3.2.2" data-path="pivoting.html"><a href="pivoting.html#用法-1"><i class="fa fa-check"></i><b>3.2.2</b> 用法</a></li>
<li class="chapter" data-level="3.2.3" data-path="pivoting.html"><a href="pivoting.html#长转宽"><i class="fa fa-check"></i><b>3.2.3</b> 长转宽</a></li>
<li class="chapter" data-level="3.2.4" data-path="pivoting.html"><a href="pivoting.html#用法-2"><i class="fa fa-check"></i><b>3.2.4</b> 用法</a></li>
</ul></li>
<li class="chapter" data-level="3.3" data-path="tidyr-rectangle.html"><a href="tidyr-rectangle.html"><i class="fa fa-check"></i><b>3.3</b> 矩形数据</a></li>
<li class="chapter" data-level="3.4" data-path="tidyr-nest-data.html"><a href="tidyr-nest-data.html"><i class="fa fa-check"></i><b>3.4</b> 嵌套数据</a>
<ul>
<li class="chapter" data-level="3.4.1" data-path="tidyr-nest-data.html"><a href="tidyr-nest-data.html#基础"><i class="fa fa-check"></i><b>3.4.1</b> 基础</a></li>
<li class="chapter" data-level="3.4.2" data-path="tidyr-nest-data.html"><a href="tidyr-nest-data.html#嵌套数据和模型"><i class="fa fa-check"></i><b>3.4.2</b> 嵌套数据和模型</a></li>
</ul></li>
<li class="chapter" data-level="3.5" data-path="character-vector.html"><a href="character-vector.html"><i class="fa fa-check"></i><b>3.5</b> 字符处理</a>
<ul>
<li class="chapter" data-level="3.5.1" data-path="character-vector.html"><a href="character-vector.html#新列提取"><i class="fa fa-check"></i><b>3.5.1</b> 新列提取</a></li>
<li class="chapter" data-level="3.5.2" data-path="character-vector.html"><a href="character-vector.html#拆分"><i class="fa fa-check"></i><b>3.5.2</b> 拆分</a></li>
<li class="chapter" data-level="3.5.3" data-path="character-vector.html"><a href="character-vector.html#列拆分行"><i class="fa fa-check"></i><b>3.5.3</b> 列拆分行</a></li>
<li class="chapter" data-level="3.5.4" data-path="character-vector.html"><a href="character-vector.html#合并多列"><i class="fa fa-check"></i><b>3.5.4</b> 合并多列</a></li>
</ul></li>
<li class="chapter" data-level="3.6" data-path="tidyr-expand.html"><a href="tidyr-expand.html"><i class="fa fa-check"></i><b>3.6</b> 扩展数据框</a></li>
<li class="chapter" data-level="3.7" data-path="tidyr-fill-NA.html"><a href="tidyr-fill-NA.html"><i class="fa fa-check"></i><b>3.7</b> 缺失值</a>
<ul>
<li class="chapter" data-level="3.7.1" data-path="tidyr-fill-NA.html"><a href="tidyr-fill-NA.html#replace_na"><i class="fa fa-check"></i><b>3.7.1</b> replace_na</a></li>
<li class="chapter" data-level="3.7.2" data-path="tidyr-fill-NA.html"><a href="tidyr-fill-NA.html#fill"><i class="fa fa-check"></i><b>3.7.2</b> fill</a></li>
<li class="chapter" data-level="3.7.3" data-path="tidyr-fill-NA.html"><a href="tidyr-fill-NA.html#drop_na"><i class="fa fa-check"></i><b>3.7.3</b> drop_na</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="4" data-path="character-handling.html"><a href="character-handling.html"><i class="fa fa-check"></i><b>4</b> 字符处理</a>
<ul>
<li class="chapter" data-level="4.1" data-path="character-base-R.html"><a href="character-base-R.html"><i class="fa fa-check"></i><b>4.1</b> base R</a>
<ul>
<li class="chapter" data-level="4.1.1" data-path="character-base-R.html"><a href="character-base-R.html#单双引号"><i class="fa fa-check"></i><b>4.1.1</b> 单双引号</a></li>
<li class="chapter" data-level="4.1.2" data-path="character-base-R.html"><a href="character-base-R.html#转义"><i class="fa fa-check"></i><b>4.1.2</b> 转义</a></li>
<li class="chapter" data-level="4.1.3" data-path="character-base-R.html"><a href="character-base-R.html#常用函数"><i class="fa fa-check"></i><b>4.1.3</b> 常用函数</a></li>
<li class="chapter" data-level="4.1.4" data-path="character-base-R.html"><a href="character-base-R.html#newfeatures"><i class="fa fa-check"></i><b>4.1.4</b> 新特性</a></li>
</ul></li>
<li class="chapter" data-level="4.2" data-path="character-stringr-packages.html"><a href="character-stringr-packages.html"><i class="fa fa-check"></i><b>4.2</b> stringr</a>
<ul>
<li class="chapter" data-level="4.2.1" data-path="character-stringr-packages.html"><a href="character-stringr-packages.html#stringr-install"><i class="fa fa-check"></i><b>4.2.1</b> 安装</a></li>
<li class="chapter" data-level="4.2.2" data-path="character-stringr-packages.html"><a href="character-stringr-packages.html#stringr-usage"><i class="fa fa-check"></i><b>4.2.2</b> 基本使用</a></li>
<li class="chapter" data-level="4.2.3" data-path="character-stringr-packages.html"><a href="character-stringr-packages.html#stringr-functions"><i class="fa fa-check"></i><b>4.2.3</b> 常用函数</a></li>
</ul></li>
<li class="chapter" data-level="4.3" data-path="character-application.html"><a href="character-application.html"><i class="fa fa-check"></i><b>4.3</b> 综合运用</a>
<ul>
<li class="chapter" data-level="4.3.1" data-path="character-application.html"><a href="character-application.html#实现excel函数"><i class="fa fa-check"></i><b>4.3.1</b> 实现excel函数</a></li>
<li class="chapter" data-level="4.3.2" data-path="character-application.html"><a href="character-application.html#使用案例"><i class="fa fa-check"></i><b>4.3.2</b> 使用案例</a></li>
</ul></li>
<li class="chapter" data-level="4.4" data-path="character-the-difference-stringr-and-base.html"><a href="character-the-difference-stringr-and-base.html"><i class="fa fa-check"></i><b>4.4</b> base 和 stringr</a></li>
<li class="chapter" data-level="4.5" data-path="character-reference-material.html"><a href="character-reference-material.html"><i class="fa fa-check"></i><b>4.5</b> 参考资料</a></li>
</ul></li>
<li class="chapter" data-level="5" data-path="datetime.html"><a href="datetime.html"><i class="fa fa-check"></i><b>5</b> 时间处理</a>
<ul>
<li class="chapter" data-level="5.1" data-path="datetime-base-R.html"><a href="datetime-base-R.html"><i class="fa fa-check"></i><b>5.1</b> base R</a>
<ul>
<li class="chapter" data-level="5.1.1" data-path="datetime-base-R.html"><a href="datetime-base-R.html#the-date-class"><i class="fa fa-check"></i><b>5.1.1</b> Date</a></li>
<li class="chapter" data-level="5.1.2" data-path="datetime-base-R.html"><a href="datetime-base-R.html#the-POSIXct-class"><i class="fa fa-check"></i><b>5.1.2</b> POSIXct</a></li>
<li class="chapter" data-level="5.1.3" data-path="datetime-base-R.html"><a href="datetime-base-R.html#the-POSIXlt-class"><i class="fa fa-check"></i><b>5.1.3</b> POSIXlt</a></li>
</ul></li>
<li class="chapter" data-level="5.2" data-path="lubridate.html"><a href="lubridate.html"><i class="fa fa-check"></i><b>5.2</b> lubridate</a>
<ul>
<li class="chapter" data-level="5.2.1" data-path="lubridate.html"><a href="lubridate.html#lubridate-install"><i class="fa fa-check"></i><b>5.2.1</b> 安装包</a></li>
<li class="chapter" data-level="5.2.2" data-path="lubridate.html"><a href="lubridate.html#get-current-datetime"><i class="fa fa-check"></i><b>5.2.2</b> 当前时间日期</a></li>
<li class="chapter" data-level="5.2.3" data-path="lubridate.html"><a href="lubridate.html#make-datetime"><i class="fa fa-check"></i><b>5.2.3</b> 构造日期时间</a></li>
<li class="chapter" data-level="5.2.4" data-path="lubridate.html"><a href="lubridate.html#parse-datetime"><i class="fa fa-check"></i><b>5.2.4</b> 解析日期时间</a></li>
<li class="chapter" data-level="5.2.5" data-path="lubridate.html"><a href="lubridate.html#extracting-datetime-information"><i class="fa fa-check"></i><b>5.2.5</b> 提取日期时间成分</a></li>
<li class="chapter" data-level="5.2.6" data-path="lubridate.html"><a href="lubridate.html#time-zones"><i class="fa fa-check"></i><b>5.2.6</b> 处理时区</a></li>
<li class="chapter" data-level="5.2.7" data-path="lubridate.html"><a href="lubridate.html#interveal"><i class="fa fa-check"></i><b>5.2.7</b> 时间间隔</a></li>
<li class="chapter" data-level="5.2.8" data-path="lubridate.html"><a href="lubridate.html#calculate-datetime"><i class="fa fa-check"></i><b>5.2.8</b> 时间日期计算</a></li>
</ul></li>
<li class="chapter" data-level="5.3" data-path="datetime-application.html"><a href="datetime-application.html"><i class="fa fa-check"></i><b>5.3</b> 综合运用</a>
<ul>
<li class="chapter" data-level="5.3.1" data-path="datetime-application.html"><a href="datetime-application.html#日报同环比计算"><i class="fa fa-check"></i><b>5.3.1</b> 日报同环比计算</a></li>
<li class="chapter" data-level="5.3.2" data-path="datetime-application.html"><a href="datetime-application.html#清洗不同类型日期格式"><i class="fa fa-check"></i><b>5.3.2</b> 清洗不同类型日期格式</a></li>
<li class="chapter" data-level="5.3.3" data-path="datetime-application.html"><a href="datetime-application.html#扫码后中奖时间匹配"><i class="fa fa-check"></i><b>5.3.3</b> 扫码后中奖时间匹配</a></li>
</ul></li>
<li class="chapter" data-level="5.4" data-path="datetime-additional-information.html"><a href="datetime-additional-information.html"><i class="fa fa-check"></i><b>5.4</b> 补充资料</a>
<ul>
<li class="chapter" data-level="5.4.1" data-path="datetime-additional-information.html"><a href="datetime-additional-information.html#excel-and-r"><i class="fa fa-check"></i><b>5.4.1</b> Excel and R</a></li>
<li class="chapter" data-level="5.4.2" data-path="datetime-additional-information.html"><a href="datetime-additional-information.html#参考资料-1"><i class="fa fa-check"></i><b>5.4.2</b> 参考资料</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="6" data-path="forcats.html"><a href="forcats.html"><i class="fa fa-check"></i><b>6</b> 因子介绍</a>
<ul>
<li class="chapter" data-level="6.1" data-path="forcats-introduction.html"><a href="forcats-introduction.html"><i class="fa fa-check"></i><b>6.1</b> 介绍</a>
<ul>
<li class="chapter" data-level="6.1.1" data-path="forcats-introduction.html"><a href="forcats-introduction.html#forcats:install"><i class="fa fa-check"></i><b>6.1.1</b> 安装</a></li>
</ul></li>
<li class="chapter" data-level="6.2" data-path="forcats-usage.html"><a href="forcats-usage.html"><i class="fa fa-check"></i><b>6.2</b> 用法</a>
<ul>
<li class="chapter" data-level="6.2.1" data-path="forcats-usage.html"><a href="forcats-usage.html#创建因子"><i class="fa fa-check"></i><b>6.2.1</b> 创建因子</a></li>
<li class="chapter" data-level="6.2.2" data-path="forcats-usage.html"><a href="forcats-usage.html#修改因子顺序"><i class="fa fa-check"></i><b>6.2.2</b> 修改因子顺序</a></li>
<li class="chapter" data-level="6.2.3" data-path="forcats-usage.html"><a href="forcats-usage.html#修改因子级别"><i class="fa fa-check"></i><b>6.2.3</b> 修改因子级别</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="7" data-path="Data-Manipulation-datatable.html"><a href="Data-Manipulation-datatable.html"><i class="fa fa-check"></i><b>7</b> data.table</a>
<ul>
<li class="chapter" data-level="7.1" data-path="datatable-description.html"><a href="datatable-description.html"><i class="fa fa-check"></i><b>7.1</b> 基础介绍</a>
<ul>
<li class="chapter" data-level="7.1.1" data-path="datatable-description.html"><a href="datatable-description.html#读取数据"><i class="fa fa-check"></i><b>7.1.1</b> 读取数据</a></li>
<li class="chapter" data-level="7.1.2" data-path="datatable-description.html"><a href="datatable-description.html#基本格式"><i class="fa fa-check"></i><b>7.1.2</b> 基本格式</a></li>
<li class="chapter" data-level="7.1.3" data-path="datatable-description.html"><a href="datatable-description.html#i-j-by-使用"><i class="fa fa-check"></i><b>7.1.3</b> i j by 使用</a></li>
<li class="chapter" data-level="7.1.4" data-path="datatable-description.html"><a href="datatable-description.html#行列筛选总结"><i class="fa fa-check"></i><b>7.1.4</b> 行列筛选总结</a></li>
</ul></li>
<li class="chapter" data-level="7.2" data-path="datatable-usage.html"><a href="datatable-usage.html"><i class="fa fa-check"></i><b>7.2</b> 常规操作</a>
<ul>
<li class="chapter" data-level="7.2.1" data-path="datatable-usage.html"><a href="datatable-usage.html#行筛选"><i class="fa fa-check"></i><b>7.2.1</b> 行筛选</a></li>
<li class="chapter" data-level="7.2.2" data-path="datatable-usage.html"><a href="datatable-usage.html#新增更新列"><i class="fa fa-check"></i><b>7.2.2</b> 新增更新列</a></li>
<li class="chapter" data-level="7.2.3" data-path="datatable-usage.html"><a href="datatable-usage.html#排序"><i class="fa fa-check"></i><b>7.2.3</b> 排序</a></li>
</ul></li>
<li class="chapter" data-level="7.3" data-path="datatable-function.html"><a href="datatable-function.html"><i class="fa fa-check"></i><b>7.3</b> 常用函数</a>
<ul>
<li class="chapter" data-level="7.3.1" data-path="datatable-function.html"><a href="datatable-function.html#特殊符号"><i class="fa fa-check"></i><b>7.3.1</b> 特殊符号</a></li>
<li class="chapter" data-level="7.3.2" data-path="datatable-function.html"><a href="datatable-function.html#排序函数-1"><i class="fa fa-check"></i><b>7.3.2</b> 排序函数</a></li>
<li class="chapter" data-level="7.3.3" data-path="datatable-function.html"><a href="datatable-function.html#非重复计数"><i class="fa fa-check"></i><b>7.3.3</b> 非重复计数</a></li>
<li class="chapter" data-level="7.3.4" data-path="datatable-function.html"><a href="datatable-function.html#判断函数"><i class="fa fa-check"></i><b>7.3.4</b> 判断函数</a></li>
<li class="chapter" data-level="7.3.5" data-path="datatable-function.html"><a href="datatable-function.html#交集-差集-合并"><i class="fa fa-check"></i><b>7.3.5</b> 交集 差集 合并</a></li>
<li class="chapter" data-level="7.3.6" data-path="datatable-function.html"><a href="datatable-function.html#长宽转换"><i class="fa fa-check"></i><b>7.3.6</b> 长宽转换</a></li>
<li class="chapter" data-level="7.3.7" data-path="datatable-function.html"><a href="datatable-function.html#表连接"><i class="fa fa-check"></i><b>7.3.7</b> 表连接</a></li>
</ul></li>
<li class="chapter" data-level="7.4" data-path="datatable-advanced-functions.html"><a href="datatable-advanced-functions.html"><i class="fa fa-check"></i><b>7.4</b> 高级函数</a>
<ul>
<li class="chapter" data-level="7.4.1" data-path="datatable-advanced-functions.html"><a href="datatable-advanced-functions.html#groupingsets"><i class="fa fa-check"></i><b>7.4.1</b> groupingsets</a></li>
<li class="chapter" data-level="7.4.2" data-path="datatable-advanced-functions.html"><a href="datatable-advanced-functions.html#rleid"><i class="fa fa-check"></i><b>7.4.2</b> rleid</a></li>
<li class="chapter" data-level="7.4.3" data-path="datatable-advanced-functions.html"><a href="datatable-advanced-functions.html#shift"><i class="fa fa-check"></i><b>7.4.3</b> shift</a></li>
<li class="chapter" data-level="7.4.4" data-path="datatable-advanced-functions.html"><a href="datatable-advanced-functions.html#j"><i class="fa fa-check"></i><b>7.4.4</b> J</a></li>
</ul></li>
<li class="chapter" data-level="7.5" data-path="datatable-tips.html"><a href="datatable-tips.html"><i class="fa fa-check"></i><b>7.5</b> 小技巧</a>
<ul>
<li class="chapter" data-level="7.5.1" data-path="datatable-tips.html"><a href="datatable-tips.html#用抑制中间过程输出"><i class="fa fa-check"></i><b>7.5.1</b> 用{}抑制中间过程输出</a></li>
<li class="chapter" data-level="7.5.2" data-path="datatable-tips.html"><a href="datatable-tips.html#使用打印data.table"><i class="fa fa-check"></i><b>7.5.2</b> 使用[]打印data.table</a></li>
</ul></li>
<li class="chapter" data-level="7.6" data-path="datatable-application.html"><a href="datatable-application.html"><i class="fa fa-check"></i><b>7.6</b> 运用</a>
<ul>
<li class="chapter" data-level="7.6.1" data-path="datatable-application.html"><a href="datatable-application.html#自定义函数计算"><i class="fa fa-check"></i><b>7.6.1</b> 自定义函数计算</a></li>
<li class="chapter" data-level="7.6.2" data-path="datatable-application.html"><a href="datatable-application.html#带汇总的聚合运算"><i class="fa fa-check"></i><b>7.6.2</b> 带汇总的聚合运算</a></li>
<li class="chapter" data-level="7.6.3" data-path="datatable-application.html"><a href="datatable-application.html#行列转变"><i class="fa fa-check"></i><b>7.6.3</b> 行列转变</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="8" data-path="database.html"><a href="database.html"><i class="fa fa-check"></i><b>8</b> database</a>
<ul>
<li class="chapter" data-level="8.1" data-path="database-install.html"><a href="database-install.html"><i class="fa fa-check"></i><b>8.1</b> 安装数据库</a></li>
<li class="chapter" data-level="8.2" data-path="database-odbc-package.html"><a href="database-odbc-package.html"><i class="fa fa-check"></i><b>8.2</b> odbc包</a>
<ul>
<li class="chapter" data-level="8.2.1" data-path="database-odbc-package.html"><a href="database-odbc-package.html#安装包"><i class="fa fa-check"></i><b>8.2.1</b> 安装包</a></li>
<li class="chapter" data-level="8.2.2" data-path="database-odbc-package.html"><a href="database-odbc-package.html#驱动安装"><i class="fa fa-check"></i><b>8.2.2</b> 驱动安装</a></li>
<li class="chapter" data-level="8.2.3" data-path="database-odbc-package.html"><a href="database-odbc-package.html#连接数据库"><i class="fa fa-check"></i><b>8.2.3</b> 连接数据库</a></li>
<li class="chapter" data-level="8.2.4" data-path="database-odbc-package.html"><a href="database-odbc-package.html#读写数据库"><i class="fa fa-check"></i><b>8.2.4</b> 读写数据库</a></li>
</ul></li>
<li class="chapter" data-level="8.3" data-path="database-DBI-package.html"><a href="database-DBI-package.html"><i class="fa fa-check"></i><b>8.3</b> DBI包</a>
<ul>
<li class="chapter" data-level="8.3.1" data-path="database-DBI-package.html"><a href="database-DBI-package.html#安装-1"><i class="fa fa-check"></i><b>8.3.1</b> 安装</a></li>
<li class="chapter" data-level="8.3.2" data-path="database-DBI-package.html"><a href="database-DBI-package.html#连接数据库-1"><i class="fa fa-check"></i><b>8.3.2</b> 连接数据库</a></li>
<li class="chapter" data-level="8.3.3" data-path="database-DBI-package.html"><a href="database-DBI-package.html#读写数据库-1"><i class="fa fa-check"></i><b>8.3.3</b> 读写数据库</a></li>
<li class="chapter" data-level="8.3.4" data-path="database-DBI-package.html"><a href="database-DBI-package.html#其它函数介绍"><i class="fa fa-check"></i><b>8.3.4</b> 其它函数介绍</a></li>
</ul></li>
<li class="chapter" data-level="8.4" data-path="database-else-package.html"><a href="database-else-package.html"><i class="fa fa-check"></i><b>8.4</b> 其他R包</a>
<ul>
<li class="chapter" data-level="8.4.1" data-path="database-else-package.html"><a href="database-else-package.html#rodbc包"><i class="fa fa-check"></i><b>8.4.1</b> RODBC包</a></li>
<li class="chapter" data-level="8.4.2" data-path="database-else-package.html"><a href="database-else-package.html#roracle包"><i class="fa fa-check"></i><b>8.4.2</b> ROracle包</a></li>
<li class="chapter" data-level="8.4.3" data-path="database-else-package.html"><a href="database-else-package.html#rmysql包"><i class="fa fa-check"></i><b>8.4.3</b> RMySQL包</a></li>
<li class="chapter" data-level="8.4.4" data-path="database-else-package.html"><a href="database-else-package.html#rsqlite"><i class="fa fa-check"></i><b>8.4.4</b> RSQLite</a></li>
</ul></li>
<li class="chapter" data-level="8.5" data-path="database-big-data.html"><a href="database-big-data.html"><i class="fa fa-check"></i><b>8.5</b> 大数据相关R包</a>
<ul>
<li class="chapter" data-level="8.5.1" data-path="database-big-data.html"><a href="database-big-data.html#sparklyr"><i class="fa fa-check"></i><b>8.5.1</b> sparklyr</a></li>
<li class="chapter" data-level="8.5.2" data-path="database-big-data.html"><a href="database-big-data.html#RClickhouse"><i class="fa fa-check"></i><b>8.5.2</b> RClickhouse</a></li>
</ul></li>
<li class="chapter" data-level="8.6" data-path="database-FAQ.html"><a href="database-FAQ.html"><i class="fa fa-check"></i><b>8.6</b> 常见问题</a>
<ul>
<li class="chapter" data-level="8.6.1" data-path="database-FAQ.html"><a href="database-FAQ.html#乱码问题"><i class="fa fa-check"></i><b>8.6.1</b> 乱码问题</a></li>
<li class="chapter" data-level="8.6.2" data-path="database-FAQ.html"><a href="database-FAQ.html#无法连接问题"><i class="fa fa-check"></i><b>8.6.2</b> 无法连接问题</a></li>
<li class="chapter" data-level="8.6.3" data-path="database-FAQ.html"><a href="database-FAQ.html#远程连接"><i class="fa fa-check"></i><b>8.6.3</b> 远程连接</a></li>
<li class="chapter" data-level="8.6.4" data-path="database-FAQ.html"><a href="database-FAQ.html#跳板机连接"><i class="fa fa-check"></i><b>8.6.4</b> 跳板机连接</a></li>
</ul></li>
<li class="chapter" data-level="8.7" data-path="database-dbplyr-package.html"><a href="database-dbplyr-package.html"><i class="fa fa-check"></i><b>8.7</b> dbplyr</a>
<ul>
<li class="chapter" data-level="8.7.1" data-path="database-dbplyr-package.html"><a href="database-dbplyr-package.html#安装-2"><i class="fa fa-check"></i><b>8.7.1</b> 安装</a></li>
<li class="chapter" data-level="8.7.2" data-path="database-dbplyr-package.html"><a href="database-dbplyr-package.html#基础用法-1"><i class="fa fa-check"></i><b>8.7.2</b> 基础用法</a></li>
<li class="chapter" data-level="8.7.3" data-path="database-dbplyr-package.html"><a href="database-dbplyr-package.html#无法正确转化"><i class="fa fa-check"></i><b>8.7.3</b> 无法正确转化</a></li>
</ul></li>
<li class="chapter" data-level="8.8" data-path="database-reference-material.html"><a href="database-reference-material.html"><i class="fa fa-check"></i><b>8.8</b> 参考资料</a></li>
</ul></li>
<li class="chapter" data-level="9" data-path="R-loop-structure.html"><a href="R-loop-structure.html"><i class="fa fa-check"></i><b>9</b> 循环结构</a>
<ul>
<li class="chapter" data-level="9.1" data-path="R-loop-description.html"><a href="R-loop-description.html"><i class="fa fa-check"></i><b>9.1</b> R循环介绍</a>
<ul>
<li class="chapter" data-level="9.1.1" data-path="R-loop-description.html"><a href="R-loop-description.html#R:loop-example"><i class="fa fa-check"></i><b>9.1.1</b> 简单示例</a></li>
<li class="chapter" data-level="9.1.2" data-path="R-loop-description.html"><a href="R-loop-description.html#three:loop-structure"><i class="fa fa-check"></i><b>9.1.2</b> 循环结构</a></li>
<li class="chapter" data-level="9.1.3" data-path="R-loop-description.html"><a href="R-loop-description.html#loop:control"><i class="fa fa-check"></i><b>9.1.3</b> 循环控制</a></li>
<li class="chapter" data-level="9.1.4" data-path="R-loop-description.html"><a href="R-loop-description.html#嵌套循环"><i class="fa fa-check"></i><b>9.1.4</b> 嵌套循环</a></li>
</ul></li>
<li class="chapter" data-level="9.2" data-path="loop-changes.html"><a href="loop-changes.html"><i class="fa fa-check"></i><b>9.2</b> 循环变化</a>
<ul>
<li class="chapter" data-level="9.2.1" data-path="loop-changes.html"><a href="loop-changes.html#修改已有对象"><i class="fa fa-check"></i><b>9.2.1</b> 修改已有对象</a></li>
<li class="chapter" data-level="9.2.2" data-path="loop-changes.html"><a href="loop-changes.html#循环模式"><i class="fa fa-check"></i><b>9.2.2</b> 循环模式</a></li>
<li class="chapter" data-level="9.2.3" data-path="loop-changes.html"><a href="loop-changes.html#未知长度输出"><i class="fa fa-check"></i><b>9.2.3</b> 未知长度输出</a></li>
</ul></li>
<li class="chapter" data-level="9.3" data-path="apply-function.html"><a href="apply-function.html"><i class="fa fa-check"></i><b>9.3</b> apply系列函数</a>
<ul>
<li class="chapter" data-level="9.3.1" data-path="apply-function.html"><a href="apply-function.html#lapply"><i class="fa fa-check"></i><b>9.3.1</b> lapply 循环迭代</a></li>
<li class="chapter" data-level="9.3.2" data-path="apply-function.html"><a href="apply-function.html#sapply"><i class="fa fa-check"></i><b>9.3.2</b> sapply</a></li>
<li class="chapter" data-level="9.3.3" data-path="apply-function.html"><a href="apply-function.html#vapply"><i class="fa fa-check"></i><b>9.3.3</b> vapply 迭代安全函数</a></li>
<li class="chapter" data-level="9.3.4" data-path="apply-function.html"><a href="apply-function.html#apply"><i class="fa fa-check"></i><b>9.3.4</b> apply 多维数据</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="10" data-path="purrr-Iteration.html"><a href="purrr-Iteration.html"><i class="fa fa-check"></i><b>10</b> 循环迭代purrr介绍</a>
<ul>
<li class="chapter" data-level="10.1" data-path="安装-3.html"><a href="安装-3.html"><i class="fa fa-check"></i><b>10.1</b> 安装</a></li>
<li class="chapter" data-level="10.2" data-path="purrr-basic-usage.html"><a href="purrr-basic-usage.html"><i class="fa fa-check"></i><b>10.2</b> 常规用法</a>
<ul>
<li class="chapter" data-level="10.2.1" data-path="purrr-basic-usage.html"><a href="purrr-basic-usage.html#map-系列"><i class="fa fa-check"></i><b>10.2.1</b> map 系列</a></li>
<li class="chapter" data-level="10.2.2" data-path="purrr-basic-usage.html"><a href="purrr-basic-usage.html#pmap-系列"><i class="fa fa-check"></i><b>10.2.2</b> pmap 系列</a></li>
</ul></li>
<li class="chapter" data-level="10.3" data-path="purrr-map.html"><a href="purrr-map.html"><i class="fa fa-check"></i><b>10.3</b> map系列函数</a>
<ul>
<li class="chapter" data-level="10.3.1" data-path="purrr-map.html"><a href="purrr-map.html#用法-3"><i class="fa fa-check"></i><b>10.3.1</b> 用法</a></li>
<li class="chapter" data-level="10.3.2" data-path="purrr-map.html"><a href="purrr-map.html#案例-5"><i class="fa fa-check"></i><b>10.3.2</b> 案例</a></li>
</ul></li>
<li class="chapter" data-level="10.4" data-path="purrr-map2.html"><a href="purrr-map2.html"><i class="fa fa-check"></i><b>10.4</b> map2 系列函数</a></li>
<li class="chapter" data-level="10.5" data-path="purrr-multi-parameter.html"><a href="purrr-multi-parameter.html"><i class="fa fa-check"></i><b>10.5</b> pmap系列函数</a></li>
<li class="chapter" data-level="10.6" data-path="purrr-reduce.html"><a href="purrr-reduce.html"><i class="fa fa-check"></i><b>10.6</b> 归约累计函数</a>
<ul>
<li class="chapter" data-level="10.6.1" data-path="purrr-reduce.html"><a href="purrr-reduce.html#reduce-函数"><i class="fa fa-check"></i><b>10.6.1</b> reduce 函数</a></li>
<li class="chapter" data-level="10.6.2" data-path="purrr-reduce.html"><a href="purrr-reduce.html#accumulate-函数"><i class="fa fa-check"></i><b>10.6.2</b> accumulate 函数</a></li>
</ul></li>
<li class="chapter" data-level="10.7" data-path="purrr-safely-functions.html"><a href="purrr-safely-functions.html"><i class="fa fa-check"></i><b>10.7</b> 安全函数</a></li>
<li class="chapter" data-level="10.8" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html"><i class="fa fa-check"></i><b>10.8</b> 其他函数介绍</a>
<ul>
<li class="chapter" data-level="10.8.1" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#flatten-系列"><i class="fa fa-check"></i><b>10.8.1</b> flatten 系列</a></li>
<li class="chapter" data-level="10.8.2" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#imap-函数"><i class="fa fa-check"></i><b>10.8.2</b> imap 函数</a></li>
<li class="chapter" data-level="10.8.3" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#walk-系列"><i class="fa fa-check"></i><b>10.8.3</b> walk 系列</a></li>
<li class="chapter" data-level="10.8.4" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#逻辑判断函数"><i class="fa fa-check"></i><b>10.8.4</b> 逻辑判断函数</a></li>
<li class="chapter" data-level="10.8.5" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#提取函数"><i class="fa fa-check"></i><b>10.8.5</b> 提取函数</a></li>
<li class="chapter" data-level="10.8.6" data-path="purrr-else-functions.html"><a href="purrr-else-functions.html#筛选函数"><i class="fa fa-check"></i><b>10.8.6</b> 筛选函数</a></li>
</ul></li>
</ul></li>
<li class="chapter" data-level="11" data-path="self-define-function.html"><a href="self-define-function.html"><i class="fa fa-check"></i><b>11</b> 自定义函数</a>
<ul>
<li class="chapter" data-level="11.1" data-path="define-function-example.html"><a href="define-function-example.html"><i class="fa fa-check"></i><b>11.1</b> 简单示例</a></li>
<li class="chapter" data-level="11.2" data-path="define-function-conditional-execution.html"><a href="define-function-conditional-execution.html"><i class="fa fa-check"></i><b>11.2</b> 条件执行</a>
<ul>
<li class="chapter" data-level="11.2.1" data-path="define-function-conditional-execution.html"><a href="define-function-conditional-execution.html#多条件执行"><i class="fa fa-check"></i><b>11.2.1</b> 多条件执行</a></li>
</ul></li>
<li class="chapter" data-level="11.3" data-path="define-function-parameter.html"><a href="define-function-parameter.html"><i class="fa fa-check"></i><b>11.3</b> 函数参数</a>
<ul>
<li class="chapter" data-level="11.3.1" data-path="define-function-parameter.html"><a href="define-function-parameter.html#参数名称"><i class="fa fa-check"></i><b>11.3.1</b> 参数名称</a></li>
<li class="chapter" data-level="11.3.2" data-path="define-function-parameter.html"><a href="define-function-parameter.html#检查参数值"><i class="fa fa-check"></i><b>11.3.2</b> 检查参数值</a></li>
<li class="chapter" data-level="11.3.3" data-path="define-function-parameter.html"><a href="define-function-parameter.html#参数-5"><i class="fa fa-check"></i><b>11.3.3</b> …参数</a></li>
</ul></li>
<li class="chapter" data-level="11.4" data-path="function-return.html"><a href="function-return.html"><i class="fa fa-check"></i><b>11.4</b> 返回值</a>
<ul>
<li class="chapter" data-level="11.4.1" data-path="function-return.html"><a href="function-return.html#显式返回"><i class="fa fa-check"></i><b>11.4.1</b> 显式返回</a></li>
<li class="chapter" data-level="11.4.2" data-path="function-return.html"><a href="function-return.html#编写管道函数"><i class="fa fa-check"></i><b>11.4.2</b> 编写管道函数</a></li>
</ul></li>
<li class="chapter" data-level="11.5" data-path="function-environment.html"><a href="function-environment.html"><i class="fa fa-check"></i><b>11.5</b> 环境</a></li>
<li class="chapter" data-level="11.6" data-path="function-expand.html"><a href="function-expand.html"><i class="fa fa-check"></i><b>11.6</b> 拓展部分</a></li>
</ul></li>
<li class="chapter" data-level="12" data-path="file-system-operation.html"><a href="file-system-operation.html"><i class="fa fa-check"></i><b>12</b> R语言文件系统操作</a>
<ul>
<li class="chapter" data-level="12.1" data-path="file-base-r.html"><a href="file-base-r.html"><i class="fa fa-check"></i><b>12.1</b> base R</a>
<ul>
<li class="chapter" data-level="12.1.1" data-path="file-base-r.html"><a href="file-base-r.html#base:r-usage"><i class="fa fa-check"></i><b>12.1.1</b> 用法</a></li>
</ul></li>
<li class="chapter" data-level="12.2" data-path="fs-package.html"><a href="fs-package.html"><i class="fa fa-check"></i><b>12.2</b> fs package</a>
<ul>
<li class="chapter" data-level="12.2.1" data-path="fs-package.html"><a href="fs-package.html#fs-install"><i class="fa fa-check"></i><b>12.2.1</b> 安装</a></li>
<li class="chapter" data-level="12.2.2" data-path="fs-package.html"><a href="fs-package.html#fs-advanced"><i class="fa fa-check"></i><b>12.2.2</b> 优势</a></li>
<li class="chapter" data-level="12.2.3" data-path="fs-package.html"><a href="fs-package.html#fs-usage"><i class="fa fa-check"></i><b>12.2.3</b> 基础用法</a></li>
</ul></li>
<li class="chapter" data-level="12.3" data-path="fs-functions.html"><a href="fs-functions.html"><i class="fa fa-check"></i><b>12.3</b> fs函数介绍</a>
<ul>
<li class="chapter" data-level="12.3.1" data-path="fs-functions.html"><a href="fs-functions.html#fs-file-manipulation"><i class="fa fa-check"></i><b>12.3.1</b> 文件操作</a></li>
<li class="chapter" data-level="12.3.2" data-path="fs-functions.html"><a href="fs-functions.html#fs-dir-manipulation"><i class="fa fa-check"></i><b>12.3.2</b> 目录操作</a></li>
<li class="chapter" data-level="12.3.3" data-path="fs-functions.html"><a href="fs-functions.html#fs-link-manipulation"><i class="fa fa-check"></i><b>12.3.3</b> 链接操作</a></li>
<li class="chapter" data-level="12.3.4" data-path="fs-functions.html"><a href="fs-functions.html#fs-path-manipulation"><i class="fa fa-check"></i><b>12.3.4</b> 路径操作</a></li>
<li class="chapter" data-level="12.3.5" data-path="fs-functions.html"><a href="fs-functions.html#fs-help-manipulation"><i class="fa fa-check"></i><b>12.3.5</b> 辅助函数</a></li>
</ul></li>
<li class="chapter" data-level="12.4" data-path="file-base-fs-difference.html"><a href="file-base-fs-difference.html"><i class="fa fa-check"></i><b>12.4</b> base-fs-shell比较</a></li>
<li class="chapter" data-level="12.5" data-path="file-manipulation-reference-material.html"><a href="file-manipulation-reference-material.html"><i class="fa fa-check"></i><b>12.5</b> 参考资料</a></li>
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<div id="character:stringr-packages" class="section level2" number="4.2">
<h2><span class="header-section-number">4.2</span> stringr</h2>
<p>本小节介绍 R 包<code>stringr</code>，stringr 包的函数处理字符相对简单，并且是tidyverse系列的一部分，是很成熟的R包，API功能稳定。stringr是基于<code>stringi</code>之上构建的,stringr包集合了常见字符功能函数，如果发现 stringr 缺少某些功能可以查看<code>stringi</code>包。</p>
<p>如上文所说，字符串处理的难点，个人觉得在于正则表达式的掌握程度。对大部分常规商业数据分析工作者的面对的表格数据而言，字符处理可能仅仅只是合并、剔除、删除空格、倒叙等基础操作，所以stringr 包基本满足字符处理需求。</p>
<p>如果不熟悉R中的字符串，可以从<a href="https://r4ds.had.co.nz/strings.html">R for Data Science</a>的字符串部分开始学习，本小节的部分案例照搬<a href="https://r4ds.had.co.nz/strings.html">R for Data Science</a>。</p>
<div id="stringr-install" class="section level3" number="4.2.1">
<h3><span class="header-section-number">4.2.1</span> 安装</h3>
<p>从 CRAN 安装发行版或者是通过 github 安装开发版。</p>
<div class="sourceCode" id="cb274"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb274-1"><a href="character-stringr-packages.html#cb274-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Install the released version from CRAN:</span></span>
<span id="cb274-2"><a href="character-stringr-packages.html#cb274-2" aria-hidden="true" tabindex="-1"></a><span class="fu">install.packages</span>(<span class="st">&quot;stringr&quot;</span>)</span>
<span id="cb274-3"><a href="character-stringr-packages.html#cb274-3" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb274-4"><a href="character-stringr-packages.html#cb274-4" aria-hidden="true" tabindex="-1"></a><span class="co"># Install the cutting edge development version from GitHub:</span></span>
<span id="cb274-5"><a href="character-stringr-packages.html#cb274-5" aria-hidden="true" tabindex="-1"></a><span class="co"># install.packages(&quot;devtools&quot;)</span></span>
<span id="cb274-6"><a href="character-stringr-packages.html#cb274-6" aria-hidden="true" tabindex="-1"></a>devtools<span class="sc">::</span><span class="fu">install_github</span>(<span class="st">&quot;tidyverse/stringr&quot;</span>)</span></code></pre></div>
</div>
<div id="stringr-usage" class="section level3" number="4.2.2">
<h3><span class="header-section-number">4.2.2</span> 基本使用</h3>
<p>stringr包中所有的函数都已<code>str_</code>开头，让待处理字符做第一个参数，这样处理好处明显，方便使用以及记忆。</p>
<ul>
<li>字符串长度</li>
</ul>
<div class="sourceCode" id="cb275"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb275-1"><a href="character-stringr-packages.html#cb275-1" aria-hidden="true" tabindex="-1"></a><span class="fu">library</span>(stringr)</span>
<span id="cb275-2"><a href="character-stringr-packages.html#cb275-2" aria-hidden="true" tabindex="-1"></a>char <span class="ot">&lt;-</span> <span class="st">&quot;我是R语言学习者&quot;</span></span>
<span id="cb275-3"><a href="character-stringr-packages.html#cb275-3" aria-hidden="true" tabindex="-1"></a><span class="fu">str_length</span>(char)</span>
<span id="cb275-4"><a href="character-stringr-packages.html#cb275-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] 8</span></span>
<span id="cb275-5"><a href="character-stringr-packages.html#cb275-5" aria-hidden="true" tabindex="-1"></a><span class="co"># 向量化</span></span>
<span id="cb275-6"><a href="character-stringr-packages.html#cb275-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_length</span>(<span class="fu">c</span>(<span class="st">&quot;a&quot;</span>, <span class="st">&quot;R for data science&quot;</span>, <span class="cn">NA</span>))</span>
<span id="cb275-7"><a href="character-stringr-packages.html#cb275-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1]  1 18 NA</span></span></code></pre></div>
<ul>
<li>连接字符串</li>
</ul>
<p>R中字符串不像python中可以用加号连接字符串,如下所示:</p>
<p>R 版本</p>
<div class="sourceCode" id="cb276"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb276-1"><a href="character-stringr-packages.html#cb276-1" aria-hidden="true" tabindex="-1"></a><span class="co">#base R</span></span>
<span id="cb276-2"><a href="character-stringr-packages.html#cb276-2" aria-hidden="true" tabindex="-1"></a><span class="fu">paste0</span>(<span class="st">&#39;a&#39;</span>,<span class="st">&#39;b&#39;</span>)</span>
<span id="cb276-3"><a href="character-stringr-packages.html#cb276-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ab&quot;</span></span>
<span id="cb276-4"><a href="character-stringr-packages.html#cb276-4" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb276-5"><a href="character-stringr-packages.html#cb276-5" aria-hidden="true" tabindex="-1"></a><span class="co">#stringr</span></span>
<span id="cb276-6"><a href="character-stringr-packages.html#cb276-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_c</span>(<span class="st">&quot;a&quot;</span>,<span class="st">&quot;b&quot;</span>)</span>
<span id="cb276-7"><a href="character-stringr-packages.html#cb276-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ab&quot;</span></span>
<span id="cb276-8"><a href="character-stringr-packages.html#cb276-8" aria-hidden="true" tabindex="-1"></a><span class="fu">str_c</span>(<span class="st">&quot;a&quot;</span>, <span class="st">&quot;b&quot;</span>, <span class="at">sep =</span> <span class="st">&quot;, &quot;</span>) <span class="co">#sep 参数控制分隔符</span></span>
<span id="cb276-9"><a href="character-stringr-packages.html#cb276-9" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;a, b&quot;</span></span></code></pre></div>
<p>Python 版本</p>
<div class="sourceCode" id="cb277"><pre class="sourceCode python"><code class="sourceCode python"><span id="cb277-1"><a href="character-stringr-packages.html#cb277-1" aria-hidden="true" tabindex="-1"></a><span class="co">&#39;a&#39;</span> <span class="op">+</span> <span class="st">&#39;b&#39;</span></span>
<span id="cb277-2"><a href="character-stringr-packages.html#cb277-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; &#39;ab&#39;</span></span></code></pre></div>
<p>多个字符串合并为一个字符,<code>stringr</code>中的函数都是向量化的，合并一个和多个字符都是同样道理。</p>
<div class="sourceCode" id="cb278"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb278-1"><a href="character-stringr-packages.html#cb278-1" aria-hidden="true" tabindex="-1"></a><span class="co">#base R</span></span>
<span id="cb278-2"><a href="character-stringr-packages.html#cb278-2" aria-hidden="true" tabindex="-1"></a><span class="fu">paste0</span>(<span class="fu">c</span>(<span class="st">&#39;a&#39;</span>,<span class="st">&#39;b&#39;</span>,<span class="st">&#39;d&#39;</span>,<span class="st">&#39;e&#39;</span>),<span class="at">collapse =</span> <span class="st">&#39;,&#39;</span>)</span>
<span id="cb278-3"><a href="character-stringr-packages.html#cb278-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;a,b,d,e&quot;</span></span>
<span id="cb278-4"><a href="character-stringr-packages.html#cb278-4" aria-hidden="true" tabindex="-1"></a><span class="co">#stringr</span></span>
<span id="cb278-5"><a href="character-stringr-packages.html#cb278-5" aria-hidden="true" tabindex="-1"></a><span class="fu">str_c</span>(<span class="fu">c</span>(<span class="st">&#39;a&#39;</span>,<span class="st">&#39;b&#39;</span>,<span class="st">&#39;d&#39;</span>,<span class="st">&#39;e&#39;</span>),<span class="at">collapse =</span> <span class="st">&#39;,&#39;</span>)  <span class="co">#collapse 参数控制</span></span>
<span id="cb278-6"><a href="character-stringr-packages.html#cb278-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;a,b,d,e&quot;</span></span></code></pre></div>
<ul>
<li>移除</li>
</ul>
<p>在正则表达式中 有特殊含义,有时需要两个 ，多体会下面这段，代码实现移除“||”的功能。</p>
<div class="sourceCode" id="cb279"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb279-1"><a href="character-stringr-packages.html#cb279-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_remove</span>(<span class="at">string =</span> <span class="st">&#39;a||b&#39;</span>,<span class="at">pattern =</span> <span class="st">&quot;</span><span class="sc">\\</span><span class="st">|</span><span class="sc">\\</span><span class="st">|&quot;</span>)</span>
<span id="cb279-2"><a href="character-stringr-packages.html#cb279-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ab&quot;</span></span></code></pre></div>
<p>另外常见的\n, \t需要被转义处理,在字符清洗,如小说语义分析,网页爬虫后整理等数据清洗过程中经常用到.</p>
</div>
<div id="stringr-functions" class="section level3" number="4.2.3">
<h3><span class="header-section-number">4.2.3</span> 常用函数</h3>
<p>本小节介绍 stringr 中常用函数的用法。</p>
<div id="截取字符" class="section level4" number="4.2.3.1">
<h4><span class="header-section-number">4.2.3.1</span> 截取字符</h4>
<p>与<code>Excle</code>中<code>left</code>,<code>mid</code>,<code>right</code>函数功能类似</p>
<p>str_sub() 函数 三个参数:</p>
<p>string:需要被截取的字符串</p>
<p>start: 默认1L,即从最开始截取</p>
<p>end:默认-1L,即截取到最后</p>
<div class="sourceCode" id="cb280"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb280-1"><a href="character-stringr-packages.html#cb280-1" aria-hidden="true" tabindex="-1"></a><span class="co">#注意end 3 和 -3的区别</span></span>
<span id="cb280-2"><a href="character-stringr-packages.html#cb280-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sub</span>(<span class="at">string =</span> <span class="st">&#39;我是R语言学习者&#39;</span>,<span class="at">start =</span> <span class="dv">2</span>,<span class="at">end =</span> <span class="dv">3</span>)</span>
<span id="cb280-3"><a href="character-stringr-packages.html#cb280-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;是R&quot;</span></span>
<span id="cb280-4"><a href="character-stringr-packages.html#cb280-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sub</span>(<span class="at">string =</span> <span class="st">&#39;我是R语言学习者&#39;</span>,<span class="at">start =</span> <span class="dv">2</span>,<span class="at">end =</span> <span class="sc">-</span><span class="dv">3</span>)</span>
<span id="cb280-5"><a href="character-stringr-packages.html#cb280-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;是R语言学&quot;</span></span></code></pre></div>
</div>
<div id="匹配字符" class="section level4" number="4.2.3.2">
<h4><span class="header-section-number">4.2.3.2</span> 匹配字符</h4>
<p>查看函数帮助文档,str_match()按照指定pattern(正则表达式)查找字符。困难点在于正则表达式的编写。</p>
<div class="sourceCode" id="cb281"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb281-1"><a href="character-stringr-packages.html#cb281-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_match</span>(string, pattern)</span>
<span id="cb281-2"><a href="character-stringr-packages.html#cb281-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_match_all</span>(string, pattern)</span>
<span id="cb281-3"><a href="character-stringr-packages.html#cb281-3" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract</span>(string, pattern)</span>
<span id="cb281-4"><a href="character-stringr-packages.html#cb281-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract_all</span>(string, pattern, <span class="at">simplify =</span> <span class="cn">FALSE</span>)</span></code></pre></div>
<p>str_extract()函数返回向量,str_match()函数返回矩阵.</p>
<div class="sourceCode" id="cb282"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb282-1"><a href="character-stringr-packages.html#cb282-1" aria-hidden="true" tabindex="-1"></a><span class="co"># 测试文字来源烽火戏诸侯的&lt;剑来&gt;</span></span>
<span id="cb282-2"><a href="character-stringr-packages.html#cb282-2" aria-hidden="true" tabindex="-1"></a>strings <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&#39;陈平安放下新折的那根桃枝,吹灭蜡烛,走出屋子后,坐在台阶上,仰头望去,星空璀璨.&#39;</span>) </span>
<span id="cb282-3"><a href="character-stringr-packages.html#cb282-3" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract</span>(strings,<span class="st">&#39;陈平安&#39;</span>)</span>
<span id="cb282-4"><a href="character-stringr-packages.html#cb282-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;陈平安&quot;</span></span>
<span id="cb282-5"><a href="character-stringr-packages.html#cb282-5" aria-hidden="true" tabindex="-1"></a><span class="fu">str_match</span>(strings,<span class="st">&#39;陈平安&#39;</span>)</span>
<span id="cb282-6"><a href="character-stringr-packages.html#cb282-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;      [,1]    </span></span>
<span id="cb282-7"><a href="character-stringr-packages.html#cb282-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1,] &quot;陈平安&quot;</span></span></code></pre></div>
<ul>
<li>匹配中文</li>
</ul>
<p>匹配中文的正则表达式\[-]</p>
<div class="sourceCode" id="cb283"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb283-1"><a href="character-stringr-packages.html#cb283-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract_all</span>(strings,<span class="st">&#39;[\u4e00-\u9fa5]&#39;</span>) <span class="co">#返回list</span></span>
<span id="cb283-2"><a href="character-stringr-packages.html#cb283-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[1]]</span></span>
<span id="cb283-3"><a href="character-stringr-packages.html#cb283-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;  [1] &quot;陈&quot; &quot;平&quot; &quot;安&quot; &quot;放&quot; &quot;下&quot; &quot;新&quot; &quot;折&quot; &quot;的&quot; &quot;那&quot; &quot;根&quot; &quot;桃&quot; &quot;枝&quot; &quot;吹&quot; &quot;灭&quot; &quot;蜡&quot;</span></span>
<span id="cb283-4"><a href="character-stringr-packages.html#cb283-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [16] &quot;烛&quot; &quot;走&quot; &quot;出&quot; &quot;屋&quot; &quot;子&quot; &quot;后&quot; &quot;坐&quot; &quot;在&quot; &quot;台&quot; &quot;阶&quot; &quot;上&quot; &quot;仰&quot; &quot;头&quot; &quot;望&quot; &quot;去&quot;</span></span>
<span id="cb283-5"><a href="character-stringr-packages.html#cb283-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [31] &quot;星&quot; &quot;空&quot; &quot;璀&quot; &quot;璨&quot;</span></span></code></pre></div>
<ul>
<li>匹配数字或英文</li>
</ul>
<p>查找数字的正则表达式[0-9];查找英文的正则表达式:[a-zA-Z]</p>
<div class="sourceCode" id="cb284"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb284-1"><a href="character-stringr-packages.html#cb284-1" aria-hidden="true" tabindex="-1"></a>strings <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&#39;00123545&#39;</span>,<span class="st">&#39;LOL league of legends&#39;</span>)</span>
<span id="cb284-2"><a href="character-stringr-packages.html#cb284-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract_all</span>(strings,<span class="st">&#39;[0-9]&#39;</span>)</span>
<span id="cb284-3"><a href="character-stringr-packages.html#cb284-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[1]]</span></span>
<span id="cb284-4"><a href="character-stringr-packages.html#cb284-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;0&quot; &quot;0&quot; &quot;1&quot; &quot;2&quot; &quot;3&quot; &quot;5&quot; &quot;4&quot; &quot;5&quot;</span></span>
<span id="cb284-5"><a href="character-stringr-packages.html#cb284-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; </span></span>
<span id="cb284-6"><a href="character-stringr-packages.html#cb284-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[2]]</span></span>
<span id="cb284-7"><a href="character-stringr-packages.html#cb284-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; character(0)</span></span>
<span id="cb284-8"><a href="character-stringr-packages.html#cb284-8" aria-hidden="true" tabindex="-1"></a><span class="fu">str_extract_all</span>(strings,<span class="st">&#39;[a-zA-Z]&#39;</span>) </span>
<span id="cb284-9"><a href="character-stringr-packages.html#cb284-9" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[1]]</span></span>
<span id="cb284-10"><a href="character-stringr-packages.html#cb284-10" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; character(0)</span></span>
<span id="cb284-11"><a href="character-stringr-packages.html#cb284-11" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; </span></span>
<span id="cb284-12"><a href="character-stringr-packages.html#cb284-12" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[2]]</span></span>
<span id="cb284-13"><a href="character-stringr-packages.html#cb284-13" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;  [1] &quot;L&quot; &quot;O&quot; &quot;L&quot; &quot;l&quot; &quot;e&quot; &quot;a&quot; &quot;g&quot; &quot;u&quot; &quot;e&quot; &quot;o&quot; &quot;f&quot; &quot;l&quot; &quot;e&quot; &quot;g&quot; &quot;e&quot; &quot;n&quot; &quot;d&quot; &quot;s&quot;</span></span></code></pre></div>
</div>
<div id="添加字符" class="section level4" number="4.2.3.3">
<h4><span class="header-section-number">4.2.3.3</span> 添加字符</h4>
<p>str_pad() 函数向字符串添加字符。像工作中处理月份的时候,1,2,3,4,5,6,7,8,9,10,11,12变成01,02,03,04,05,06,07,08,09,10,11,12.按照日期时间输出文件名称,如下所示:</p>
<div class="sourceCode" id="cb285"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb285-1"><a href="character-stringr-packages.html#cb285-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_pad</span>(<span class="at">string =</span> <span class="dv">1</span><span class="sc">:</span><span class="dv">12</span>,<span class="at">width =</span> <span class="dv">2</span>,<span class="at">side =</span> <span class="st">&#39;left&#39;</span>,<span class="at">pad =</span> <span class="st">&#39;0&#39;</span>)</span>
<span id="cb285-2"><a href="character-stringr-packages.html#cb285-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;  [1] &quot;01&quot; &quot;02&quot; &quot;03&quot; &quot;04&quot; &quot;05&quot; &quot;06&quot; &quot;07&quot; &quot;08&quot; &quot;09&quot; &quot;10&quot; &quot;11&quot; &quot;12&quot;</span></span></code></pre></div>
</div>
<div id="去除空格" class="section level4" number="4.2.3.4">
<h4><span class="header-section-number">4.2.3.4</span> 去除空格</h4>
<p>与<code>excel</code>中<code>trim</code>函数功能类似，剔除字符中的空格，但是不可以剔除字符中的空格</p>
<div class="sourceCode" id="cb286"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb286-1"><a href="character-stringr-packages.html#cb286-1" aria-hidden="true" tabindex="-1"></a><span class="co"># side 可选 both  left right</span></span>
<span id="cb286-2"><a href="character-stringr-packages.html#cb286-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_trim</span>(<span class="st">&#39; ab af &#39;</span>,<span class="at">side =</span> <span class="st">&#39;both&#39;</span>)</span>
<span id="cb286-3"><a href="character-stringr-packages.html#cb286-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ab af&quot;</span></span></code></pre></div>
</div>
<div id="分割字符" class="section level4" number="4.2.3.5">
<h4><span class="header-section-number">4.2.3.5</span> 分割字符</h4>
<p><code>str_split()</code>处理后的结果是列表</p>
<div class="sourceCode" id="cb287"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb287-1"><a href="character-stringr-packages.html#cb287-1" aria-hidden="true" tabindex="-1"></a><span class="co"># 得到列表,需要向量化</span></span>
<span id="cb287-2"><a href="character-stringr-packages.html#cb287-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_split</span>(<span class="st">&quot;a,b,d,e&quot;</span>,<span class="at">pattern =</span> <span class="st">&#39;,&#39;</span>)</span>
<span id="cb287-3"><a href="character-stringr-packages.html#cb287-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[1]]</span></span>
<span id="cb287-4"><a href="character-stringr-packages.html#cb287-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;a&quot; &quot;b&quot; &quot;d&quot; &quot;e&quot;</span></span>
<span id="cb287-5"><a href="character-stringr-packages.html#cb287-5" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb287-6"><a href="character-stringr-packages.html#cb287-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_split</span>(<span class="st">&#39;ab||cd&#39;</span>,<span class="st">&#39;</span><span class="sc">\\</span><span class="st">|</span><span class="sc">\\</span><span class="st">|&#39;</span>) <span class="sc">%&gt;%</span> <span class="fu">unlist</span>()</span>
<span id="cb287-7"><a href="character-stringr-packages.html#cb287-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ab&quot; &quot;cd&quot;</span></span>
<span id="cb287-8"><a href="character-stringr-packages.html#cb287-8" aria-hidden="true" tabindex="-1"></a><span class="co"># same above</span></span>
<span id="cb287-9"><a href="character-stringr-packages.html#cb287-9" aria-hidden="true" tabindex="-1"></a><span class="co">#str_split(&#39;ab||cd&#39;,&#39;\\|\\|&#39;) %&gt;% purrr::as_vector()</span></span></code></pre></div>
<p>当待处理的字符串是字符串向量时，得到的列表长度与向量长度一致</p>
<div class="sourceCode" id="cb288"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb288-1"><a href="character-stringr-packages.html#cb288-1" aria-hidden="true" tabindex="-1"></a>fruits <span class="ot">&lt;-</span> <span class="fu">c</span>(</span>
<span id="cb288-2"><a href="character-stringr-packages.html#cb288-2" aria-hidden="true" tabindex="-1"></a>  <span class="st">&quot;apples and oranges and pears and bananas&quot;</span>,</span>
<span id="cb288-3"><a href="character-stringr-packages.html#cb288-3" aria-hidden="true" tabindex="-1"></a>  <span class="st">&quot;pineapples and mangos and guavas&quot;</span></span>
<span id="cb288-4"><a href="character-stringr-packages.html#cb288-4" aria-hidden="true" tabindex="-1"></a>)</span>
<span id="cb288-5"><a href="character-stringr-packages.html#cb288-5" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb288-6"><a href="character-stringr-packages.html#cb288-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_split</span>(fruits, <span class="st">&quot; and &quot;</span>)</span>
<span id="cb288-7"><a href="character-stringr-packages.html#cb288-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[1]]</span></span>
<span id="cb288-8"><a href="character-stringr-packages.html#cb288-8" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;apples&quot;  &quot;oranges&quot; &quot;pears&quot;   &quot;bananas&quot;</span></span>
<span id="cb288-9"><a href="character-stringr-packages.html#cb288-9" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; </span></span>
<span id="cb288-10"><a href="character-stringr-packages.html#cb288-10" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [[2]]</span></span>
<span id="cb288-11"><a href="character-stringr-packages.html#cb288-11" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;pineapples&quot; &quot;mangos&quot;     &quot;guavas&quot;</span></span></code></pre></div>
</div>
<div id="替换字符" class="section level4" number="4.2.3.6">
<h4><span class="header-section-number">4.2.3.6</span> 替换字符</h4>
<p><code>str_replace()</code>，<code>str_replace_all()</code>函数用来替换字符</p>
<div class="sourceCode" id="cb289"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb289-1"><a href="character-stringr-packages.html#cb289-1" aria-hidden="true" tabindex="-1"></a>fruits <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;one apple&quot;</span>, <span class="st">&quot;two pears&quot;</span>, <span class="st">&quot;three bananas&quot;</span>)</span>
<span id="cb289-2"><a href="character-stringr-packages.html#cb289-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_replace</span>(fruits, <span class="st">&quot;[aeiou]&quot;</span>, <span class="st">&quot;-&quot;</span>)</span>
<span id="cb289-3"><a href="character-stringr-packages.html#cb289-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;-ne apple&quot;     &quot;tw- pears&quot;     &quot;thr-e bananas&quot;</span></span>
<span id="cb289-4"><a href="character-stringr-packages.html#cb289-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_replace_all</span>(fruits, <span class="st">&quot;[aeiou]&quot;</span>, <span class="st">&quot;-&quot;</span>)</span>
<span id="cb289-5"><a href="character-stringr-packages.html#cb289-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;-n- -ppl-&quot;     &quot;tw- p--rs&quot;     &quot;thr-- b-n-n-s&quot;</span></span></code></pre></div>
</div>
<div id="移除字符" class="section level4" number="4.2.3.7">
<h4><span class="header-section-number">4.2.3.7</span> 移除字符</h4>
<p><code>str_remove()</code>,<code>str_remove_all()</code>移除字符。本人常用该函数剔除文本中的空格。</p>
<div class="sourceCode" id="cb290"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb290-1"><a href="character-stringr-packages.html#cb290-1" aria-hidden="true" tabindex="-1"></a>fruits <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;one apple&quot;</span>, <span class="st">&quot;two pears&quot;</span>, <span class="st">&quot;three bananas&quot;</span>)</span>
<span id="cb290-2"><a href="character-stringr-packages.html#cb290-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_remove</span>(fruits, <span class="st">&quot;[aeiou]&quot;</span>)</span>
<span id="cb290-3"><a href="character-stringr-packages.html#cb290-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;ne apple&quot;     &quot;tw pears&quot;     &quot;thre bananas&quot;</span></span>
<span id="cb290-4"><a href="character-stringr-packages.html#cb290-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_remove_all</span>(fruits, <span class="st">&quot;[aeiou]&quot;</span>)</span>
<span id="cb290-5"><a href="character-stringr-packages.html#cb290-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;n ppl&quot;    &quot;tw prs&quot;   &quot;thr bnns&quot;</span></span></code></pre></div>
<p>移除文本中空格</p>
<div class="sourceCode" id="cb291"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb291-1"><a href="character-stringr-packages.html#cb291-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_replace_all</span>(<span class="at">string =</span> <span class="st">&#39; d a  b &#39;</span>,<span class="at">pattern =</span> <span class="st">&#39; &#39;</span>,<span class="at">replacement =</span> <span class="st">&#39;&#39;</span>)</span>
<span id="cb291-2"><a href="character-stringr-packages.html#cb291-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;dab&quot;</span></span></code></pre></div>
</div>
<div id="字符排序" class="section level4" number="4.2.3.8">
<h4><span class="header-section-number">4.2.3.8</span> 字符排序</h4>
<p>numeric 参数决定是否按照数字排序。</p>
<div class="sourceCode" id="cb292"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb292-1"><a href="character-stringr-packages.html#cb292-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_order</span>(x, <span class="at">decreasing =</span> <span class="cn">FALSE</span>, <span class="at">na_last =</span> <span class="cn">TRUE</span>, <span class="at">locale =</span> <span class="st">&quot;en&quot;</span>,</span>
<span id="cb292-2"><a href="character-stringr-packages.html#cb292-2" aria-hidden="true" tabindex="-1"></a>  <span class="at">numeric =</span> <span class="cn">FALSE</span>, ...)</span>
<span id="cb292-3"><a href="character-stringr-packages.html#cb292-3" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb292-4"><a href="character-stringr-packages.html#cb292-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sort</span>(x, <span class="at">decreasing =</span> <span class="cn">FALSE</span>, <span class="at">na_last =</span> <span class="cn">TRUE</span>, <span class="at">locale =</span> <span class="st">&quot;en&quot;</span>,</span>
<span id="cb292-5"><a href="character-stringr-packages.html#cb292-5" aria-hidden="true" tabindex="-1"></a>  <span class="at">numeric =</span> <span class="cn">FALSE</span>, ...)</span></code></pre></div>
<div class="sourceCode" id="cb293"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb293-1"><a href="character-stringr-packages.html#cb293-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_order</span>(letters)</span>
<span id="cb293-2"><a href="character-stringr-packages.html#cb293-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25</span></span>
<span id="cb293-3"><a href="character-stringr-packages.html#cb293-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [26] 26</span></span>
<span id="cb293-4"><a href="character-stringr-packages.html#cb293-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sort</span>(letters)</span>
<span id="cb293-5"><a href="character-stringr-packages.html#cb293-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt;  [1] &quot;a&quot; &quot;b&quot; &quot;c&quot; &quot;d&quot; &quot;e&quot; &quot;f&quot; &quot;g&quot; &quot;h&quot; &quot;i&quot; &quot;j&quot; &quot;k&quot; &quot;l&quot; &quot;m&quot; &quot;n&quot; &quot;o&quot; &quot;p&quot; &quot;q&quot; &quot;r&quot; &quot;s&quot;</span></span>
<span id="cb293-6"><a href="character-stringr-packages.html#cb293-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [20] &quot;t&quot; &quot;u&quot; &quot;v&quot; &quot;w&quot; &quot;x&quot; &quot;y&quot; &quot;z&quot;</span></span></code></pre></div>
<p>numeric参数</p>
<div class="sourceCode" id="cb294"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb294-1"><a href="character-stringr-packages.html#cb294-1" aria-hidden="true" tabindex="-1"></a>x <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;100a10&quot;</span>, <span class="st">&quot;100a5&quot;</span>, <span class="st">&quot;2b&quot;</span>, <span class="st">&quot;2a&quot;</span>)</span>
<span id="cb294-2"><a href="character-stringr-packages.html#cb294-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sort</span>(x)</span>
<span id="cb294-3"><a href="character-stringr-packages.html#cb294-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;100a10&quot; &quot;100a5&quot;  &quot;2a&quot;     &quot;2b&quot;</span></span>
<span id="cb294-4"><a href="character-stringr-packages.html#cb294-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_sort</span>(x, <span class="at">numeric =</span> <span class="cn">TRUE</span>)</span>
<span id="cb294-5"><a href="character-stringr-packages.html#cb294-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;2a&quot;     &quot;2b&quot;     &quot;100a5&quot;  &quot;100a10&quot;</span></span></code></pre></div>
</div>
<div id="提取单词" class="section level4" number="4.2.3.9">
<h4><span class="header-section-number">4.2.3.9</span> 提取单词</h4>
<p>从句子中提取单词。</p>
<ul>
<li>参数</li>
</ul>
<div class="sourceCode" id="cb295"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb295-1"><a href="character-stringr-packages.html#cb295-1" aria-hidden="true" tabindex="-1"></a><span class="fu">word</span>(string, <span class="at">start =</span> 1L, <span class="at">end =</span> start, <span class="at">sep =</span> <span class="fu">fixed</span>(<span class="st">&quot; &quot;</span>))</span></code></pre></div>
<ul>
<li>案例</li>
</ul>
<div class="sourceCode" id="cb296"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb296-1"><a href="character-stringr-packages.html#cb296-1" aria-hidden="true" tabindex="-1"></a>sentences <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;Jane saw a cat&quot;</span>, <span class="st">&quot;Jane sat down&quot;</span>)</span>
<span id="cb296-2"><a href="character-stringr-packages.html#cb296-2" aria-hidden="true" tabindex="-1"></a><span class="fu">word</span>(sentences, <span class="dv">2</span>, <span class="sc">-</span><span class="dv">1</span>)</span>
<span id="cb296-3"><a href="character-stringr-packages.html#cb296-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;saw a cat&quot; &quot;sat down&quot;</span></span>
<span id="cb296-4"><a href="character-stringr-packages.html#cb296-4" aria-hidden="true" tabindex="-1"></a><span class="fu">word</span>(sentences[<span class="dv">1</span>], <span class="dv">1</span><span class="sc">:</span><span class="dv">3</span>, <span class="sc">-</span><span class="dv">1</span>)</span>
<span id="cb296-5"><a href="character-stringr-packages.html#cb296-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;Jane saw a cat&quot; &quot;saw a cat&quot;      &quot;a cat&quot;</span></span></code></pre></div>
<p>指定分隔符</p>
<div class="sourceCode" id="cb297"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb297-1"><a href="character-stringr-packages.html#cb297-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Can define words by other separators</span></span>
<span id="cb297-2"><a href="character-stringr-packages.html#cb297-2" aria-hidden="true" tabindex="-1"></a>str <span class="ot">&lt;-</span> <span class="st">&#39;abc.def..123.4568.999&#39;</span></span>
<span id="cb297-3"><a href="character-stringr-packages.html#cb297-3" aria-hidden="true" tabindex="-1"></a><span class="fu">word</span>(str, <span class="dv">1</span>, <span class="at">sep =</span> <span class="fu">fixed</span>(<span class="st">&#39;..&#39;</span>))</span>
<span id="cb297-4"><a href="character-stringr-packages.html#cb297-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;abc.def&quot;</span></span>
<span id="cb297-5"><a href="character-stringr-packages.html#cb297-5" aria-hidden="true" tabindex="-1"></a><span class="fu">word</span>(str, <span class="dv">2</span>, <span class="at">sep =</span> <span class="fu">fixed</span>(<span class="st">&#39;..&#39;</span>))</span>
<span id="cb297-6"><a href="character-stringr-packages.html#cb297-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;123.4568.999&quot;</span></span></code></pre></div>
</div>
<div id="其他函数" class="section level4" number="4.2.3.10">
<h4><span class="header-section-number">4.2.3.10</span> 其他函数</h4>
<ul>
<li>str_subset str_which</li>
</ul>
<p><code>str_subset()</code>是对x[str_detect(x,pattern)]的包装，<code>str_which()</code>是which(str_detect(x,pattern))的包装。</p>
<div class="sourceCode" id="cb298"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb298-1"><a href="character-stringr-packages.html#cb298-1" aria-hidden="true" tabindex="-1"></a>fruit <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;apple&quot;</span>, <span class="st">&quot;banana&quot;</span>, <span class="st">&quot;pear&quot;</span>, <span class="st">&quot;pinapple&quot;</span>)</span>
<span id="cb298-2"><a href="character-stringr-packages.html#cb298-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_subset</span>(fruit, <span class="st">&quot;a&quot;</span>)</span>
<span id="cb298-3"><a href="character-stringr-packages.html#cb298-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;apple&quot;    &quot;banana&quot;   &quot;pear&quot;     &quot;pinapple&quot;</span></span>
<span id="cb298-4"><a href="character-stringr-packages.html#cb298-4" aria-hidden="true" tabindex="-1"></a><span class="co"># 匹配字符首次出现的位置</span></span>
<span id="cb298-5"><a href="character-stringr-packages.html#cb298-5" aria-hidden="true" tabindex="-1"></a><span class="fu">str_which</span>(fruit, <span class="st">&quot;a&quot;</span>) </span>
<span id="cb298-6"><a href="character-stringr-packages.html#cb298-6" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] 1 2 3 4</span></span></code></pre></div>
<p>匹配字符串本身做行筛选。</p>
<div class="sourceCode" id="cb299"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb299-1"><a href="character-stringr-packages.html#cb299-1" aria-hidden="true" tabindex="-1"></a><span class="co">#筛选出字母行</span></span>
<span id="cb299-2"><a href="character-stringr-packages.html#cb299-2" aria-hidden="true" tabindex="-1"></a><span class="fu">set.seed</span>(<span class="dv">24</span>)</span>
<span id="cb299-3"><a href="character-stringr-packages.html#cb299-3" aria-hidden="true" tabindex="-1"></a>dt <span class="ot">&lt;-</span> data.table<span class="sc">::</span><span class="fu">data.table</span>(<span class="at">col=</span><span class="fu">sample</span>(<span class="fu">c</span>(letters,<span class="dv">1</span><span class="sc">:</span><span class="dv">10</span>),<span class="dv">100</span>,<span class="at">replace =</span> T))</span>
<span id="cb299-4"><a href="character-stringr-packages.html#cb299-4" aria-hidden="true" tabindex="-1"></a><span class="fu">head</span>(dt[<span class="fu">str_which</span>(col,<span class="at">pattern =</span> <span class="st">&#39;[a-z]&#39;</span>)])</span></code></pre></div>
<ul>
<li>str_dup()</li>
</ul>
<p><code>str_dup()</code>功能是复制字符串。</p>
<div class="sourceCode" id="cb300"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb300-1"><a href="character-stringr-packages.html#cb300-1" aria-hidden="true" tabindex="-1"></a>fruit <span class="ot">&lt;-</span> <span class="fu">c</span>(<span class="st">&quot;apple&quot;</span>, <span class="st">&quot;pear&quot;</span>, <span class="st">&quot;banana&quot;</span>)</span>
<span id="cb300-2"><a href="character-stringr-packages.html#cb300-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_dup</span>(fruit, <span class="dv">2</span>)</span>
<span id="cb300-3"><a href="character-stringr-packages.html#cb300-3" aria-hidden="true" tabindex="-1"></a><span class="fu">str_dup</span>(fruit, <span class="dv">1</span><span class="sc">:</span><span class="dv">3</span>)</span>
<span id="cb300-4"><a href="character-stringr-packages.html#cb300-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_c</span>(<span class="st">&quot;ba&quot;</span>, <span class="fu">str_dup</span>(<span class="st">&quot;na&quot;</span>, <span class="dv">0</span><span class="sc">:</span><span class="dv">5</span>))</span></code></pre></div>
<ul>
<li>str_starts() str_ends()</li>
</ul>
<p>从str_detect()包装得到.</p>
<div class="sourceCode" id="cb301"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb301-1"><a href="character-stringr-packages.html#cb301-1" aria-hidden="true" tabindex="-1"></a><span class="fu">str_starts</span>(<span class="st">&#39;abd&#39;</span>,<span class="st">&#39;a&#39;</span>)</span>
<span id="cb301-2"><a href="character-stringr-packages.html#cb301-2" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] TRUE</span></span>
<span id="cb301-3"><a href="character-stringr-packages.html#cb301-3" aria-hidden="true" tabindex="-1"></a><span class="fu">str_detect</span>(<span class="st">&#39;abd&#39;</span>,<span class="st">&#39;^a&#39;</span>)</span>
<span id="cb301-4"><a href="character-stringr-packages.html#cb301-4" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] TRUE</span></span>
<span id="cb301-5"><a href="character-stringr-packages.html#cb301-5" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb301-6"><a href="character-stringr-packages.html#cb301-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_ends</span>(<span class="st">&#39;abd&#39;</span>,<span class="st">&#39;d&#39;</span>)</span>
<span id="cb301-7"><a href="character-stringr-packages.html#cb301-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] TRUE</span></span>
<span id="cb301-8"><a href="character-stringr-packages.html#cb301-8" aria-hidden="true" tabindex="-1"></a><span class="fu">str_detect</span>(<span class="st">&#39;abd&#39;</span>,<span class="st">&#39;d$&#39;</span>)</span>
<span id="cb301-9"><a href="character-stringr-packages.html#cb301-9" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] TRUE</span></span></code></pre></div>
<ul>
<li>大小写转换</li>
</ul>
<p><code>str_to_upper()</code>函数将全部字符转换为大写，<code>str_to_lower()</code>函数将全部字符转换为小写，<code>str_to_title()</code>将每个单词的首字母转换为大写，<code>str_to_sentence()</code>将一个字符的首字母转换为大写。</p>
<div class="sourceCode" id="cb302"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb302-1"><a href="character-stringr-packages.html#cb302-1" aria-hidden="true" tabindex="-1"></a>dog <span class="ot">&lt;-</span> <span class="st">&quot;The quick brown dog&quot;</span></span>
<span id="cb302-2"><a href="character-stringr-packages.html#cb302-2" aria-hidden="true" tabindex="-1"></a><span class="fu">str_to_upper</span>(dog)</span>
<span id="cb302-3"><a href="character-stringr-packages.html#cb302-3" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;THE QUICK BROWN DOG&quot;</span></span>
<span id="cb302-4"><a href="character-stringr-packages.html#cb302-4" aria-hidden="true" tabindex="-1"></a><span class="fu">str_to_lower</span>(dog)</span>
<span id="cb302-5"><a href="character-stringr-packages.html#cb302-5" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;the quick brown dog&quot;</span></span>
<span id="cb302-6"><a href="character-stringr-packages.html#cb302-6" aria-hidden="true" tabindex="-1"></a><span class="fu">str_to_title</span>(dog)</span>
<span id="cb302-7"><a href="character-stringr-packages.html#cb302-7" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;The Quick Brown Dog&quot;</span></span>
<span id="cb302-8"><a href="character-stringr-packages.html#cb302-8" aria-hidden="true" tabindex="-1"></a><span class="fu">str_to_sentence</span>(<span class="st">&quot;the quick brown dog&quot;</span>)</span>
<span id="cb302-9"><a href="character-stringr-packages.html#cb302-9" aria-hidden="true" tabindex="-1"></a><span class="co">#&gt; [1] &quot;The quick brown dog&quot;</span></span></code></pre></div>
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